1. No your brother won’t be barred but that doesn’t mean guaranteed entry, it’s up to the CBP officer. Since it takes more than 14 years for your brother to get immigrant visa or GC, i130 petition wouldn’t affect much at this time for visiting.

2. Your father can try applying for returning resident visa at the US embassy with some good reasons. I doubt he will get it since it’s been so many years but who knows. If that fails, then i130 again.